/*
  The oSIP library implements the Session Initiation Protocol (SIP -rfc3261-)
  Copyright (C) 2001,2002,2003,2004,2005,2006,2007 Aymeric MOIZARD jack@atosc.org
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <osip2/internal.h>
#include <osip2/osip.h>

#include "fsm.h"

#ifndef MINISIZE

osip_statemachine_t *ist_fsm;

osip_statemachine_t *
__ist_get_fsm ()
{
  return ist_fsm;
}

void
__ist_unload_fsm ()
{
  transition_t *transition;
  osip_statemachine_t *statemachine = __ist_get_fsm ();

  for (transition = statemachine->transitions; transition != NULL; transition = statemachine->transitions)
    {
      REMOVE_ELEMENT(statemachine->transitions, transition);
      osip_free (transition);
    }

  osip_free (statemachine->transitions);
  osip_free (statemachine);
}


void
__ist_load_fsm ()
{
  transition_t *transition;

  ist_fsm = (osip_statemachine_t *) osip_malloc (sizeof (osip_statemachine_t));
  if (ist_fsm==NULL)
	  return;
  ist_fsm->transitions = NULL;

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_PRE_PROCEEDING;
  transition->type = RCV_REQINVITE;
  transition->method = (void (*)(void *, void *)) &ist_rcv_invite;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_PROCEEDING;
  transition->type = RCV_REQINVITE;
  transition->method = (void (*)(void *, void *)) &ist_rcv_invite;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_COMPLETED;
  transition->type = RCV_REQINVITE;
  transition->method = (void (*)(void *, void *)) &ist_rcv_invite;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_COMPLETED;
  transition->type = TIMEOUT_G;
  transition->method = (void (*)(void *, void *)) &osip_ist_timeout_g_event;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_COMPLETED;
  transition->type = TIMEOUT_H;
  transition->method = (void (*)(void *, void *)) &osip_ist_timeout_h_event;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_PROCEEDING;
  transition->type = SND_STATUS_1XX;
  transition->method = (void (*)(void *, void *)) &ist_snd_1xx;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_PROCEEDING;
  transition->type = SND_STATUS_2XX;
  transition->method = (void (*)(void *, void *)) &ist_snd_2xx;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_PROCEEDING;
  transition->type = SND_STATUS_3456XX;
  transition->method = (void (*)(void *, void *)) &ist_snd_3456xx;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_COMPLETED;
  transition->type = RCV_REQACK;
  transition->method = (void (*)(void *, void *)) &ist_rcv_ack;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_CONFIRMED;
  transition->type = RCV_REQACK;
  transition->method = (void (*)(void *, void *)) &ist_rcv_ack;
  ADD_ELEMENT (ist_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = IST_CONFIRMED;
  transition->type = TIMEOUT_I;
  transition->method = (void (*)(void *, void *)) &osip_ist_timeout_i_event;
  ADD_ELEMENT (ist_fsm->transitions, transition);

}

#else

transition_t ist_transition[11] =
  {
    {
      IST_PRE_PROCEEDING,
      RCV_REQINVITE,
      (void (*)(void *, void *)) &ist_rcv_invite,
      &ist_transition[1], NULL
    }
    ,
    {
      IST_PROCEEDING,
      RCV_REQINVITE,
      (void (*)(void *, void *)) &ist_rcv_invite,
      &ist_transition[2], NULL
    }
    ,
    {
      IST_COMPLETED,
      RCV_REQINVITE,
      (void (*)(void *, void *)) &ist_rcv_invite,
      &ist_transition[3], NULL
    }
    ,
    {
      IST_COMPLETED,
      TIMEOUT_G,
      (void (*)(void *, void *)) &osip_ist_timeout_g_event,
      &ist_transition[4], NULL
    }
    ,
    {
      IST_COMPLETED,
      TIMEOUT_H,
      (void (*)(void *, void *)) &osip_ist_timeout_h_event,
      &ist_transition[5], NULL
    }
    ,
    {
      IST_PROCEEDING,
      SND_STATUS_1XX,
      (void (*)(void *, void *)) &ist_snd_1xx,
      &ist_transition[6], NULL
    }
    ,
    {
      IST_PROCEEDING,
      SND_STATUS_2XX,
      (void (*)(void *, void *)) &ist_snd_2xx,
      &ist_transition[7], NULL
    }
    ,
    {
      IST_PROCEEDING,
      SND_STATUS_3456XX,
      (void (*)(void *, void *)) &ist_snd_3456xx,
      &ist_transition[8], NULL
    }
    ,
    {
      IST_COMPLETED,
      RCV_REQACK,
      (void (*)(void *, void *)) &ist_rcv_ack,
      &ist_transition[9], NULL
    }
    ,
    {
      IST_CONFIRMED,
      RCV_REQACK,
      (void (*)(void *, void *)) &ist_rcv_ack,
      &ist_transition[10], NULL
    }
    ,
    {
      IST_CONFIRMED,
      TIMEOUT_I,
      (void (*)(void *, void *)) &osip_ist_timeout_i_event,
      NULL, NULL
    }
  };

osip_statemachine_t ist_fsm = { ist_transition };

#endif

static void
ist_handle_transport_error (osip_transaction_t * ist, int err)
{
  __osip_transport_error_callback (OSIP_IST_TRANSPORT_ERROR, ist, err);
  __osip_transaction_set_state (ist, IST_TERMINATED);
  __osip_kill_transaction_callback (OSIP_IST_KILL_TRANSACTION, ist);
  /* TODO: MUST BE DELETED NOW */
}

void
ist_rcv_invite (osip_transaction_t * ist, osip_event_t * evt)
{
  int i;

  if (ist->state == IST_PRE_PROCEEDING) /* announce new INVITE */
    {
      /* Here we have ist->orig_request == NULL */
      ist->orig_request = evt->sip;

      __osip_message_callback (OSIP_IST_INVITE_RECEIVED, ist, evt->sip);
  } else                        /* IST_PROCEEDING or IST_COMPLETED */
    {
      /* delete retransmission */
      osip_message_free (evt->sip);

      __osip_message_callback (OSIP_IST_INVITE_RECEIVED_AGAIN, ist,
                               ist->orig_request);
      if (ist->last_response != NULL)   /* retransmit last response */
        {
	  i = __osip_transaction_snd_xxx(ist, ist->last_response);
          if (i != 0)
            {
              ist_handle_transport_error (ist, i);
              return;
          } else
            {
              if (MSG_IS_STATUS_1XX (ist->last_response))
                __osip_message_callback (OSIP_IST_STATUS_1XX_SENT, ist,
                                         ist->last_response);
              else if (MSG_IS_STATUS_2XX (ist->last_response))
                __osip_message_callback (OSIP_IST_STATUS_2XX_SENT_AGAIN, ist,
                                         ist->last_response);
              else
                __osip_message_callback (OSIP_IST_STATUS_3456XX_SENT_AGAIN,
                                         ist, ist->last_response);
            }
        }
      return;
    }

  /* we come here only if it was the first INVITE received */
  __osip_transaction_set_state (ist, IST_PROCEEDING);
}

void
osip_ist_timeout_g_event (osip_transaction_t * ist, osip_event_t * evt)
{
  int i;

  ist->ist_context->timer_g_length = ist->ist_context->timer_g_length * 2;
  if (ist->ist_context->timer_g_length > 4000)
    ist->ist_context->timer_g_length = 4000;
  osip_gettimeofday (&ist->ist_context->timer_g_start, NULL);
  add_gettimeofday (&ist->ist_context->timer_g_start,
                    ist->ist_context->timer_g_length);

  i = __osip_transaction_snd_xxx(ist, ist->last_response);
  if (i != 0)
    {
      ist_handle_transport_error (ist, i);
      return;
    }
  __osip_message_callback (OSIP_IST_STATUS_3456XX_SENT_AGAIN, ist,
                           ist->last_response);
}

void
osip_ist_timeout_h_event (osip_transaction_t * ist, osip_event_t * evt)
{
  ist->ist_context->timer_h_length = -1;
  ist->ist_context->timer_h_start.tv_sec = -1;

  __osip_transaction_set_state (ist, IST_TERMINATED);
  __osip_kill_transaction_callback (OSIP_IST_KILL_TRANSACTION, ist);
}

void
osip_ist_timeout_i_event (osip_transaction_t * ist, osip_event_t * evt)
{
  ist->ist_context->timer_i_length = -1;
  ist->ist_context->timer_i_start.tv_sec = -1;

  __osip_transaction_set_state (ist, IST_TERMINATED);
  __osip_kill_transaction_callback (OSIP_IST_KILL_TRANSACTION, ist);
}

void
ist_snd_1xx (osip_transaction_t * ist, osip_event_t * evt)
{
  int i;

  if (ist->last_response != NULL)
    {
      osip_message_free (ist->last_response);
    }
  ist->last_response = evt->sip;

  i = __osip_transaction_snd_xxx(ist, evt->sip);
  if (i != 0)
    {
      ist_handle_transport_error (ist, i);
      return;
  } else
    __osip_message_callback (OSIP_IST_STATUS_1XX_SENT, ist, ist->last_response);

  /* we are already in the proper state */
  return;
}

void
ist_snd_2xx (osip_transaction_t * ist, osip_event_t * evt)
{
  int i;

  if (ist->last_response != NULL)
    {
      osip_message_free (ist->last_response);
    }
  ist->last_response = evt->sip;

  i = __osip_transaction_snd_xxx(ist, evt->sip);
  if (i != 0)
    {
      ist_handle_transport_error (ist, i);
      return;
  } else
    {
      __osip_message_callback (OSIP_IST_STATUS_2XX_SENT, ist, ist->last_response);
      __osip_transaction_set_state (ist, IST_TERMINATED);
      __osip_kill_transaction_callback (OSIP_IST_KILL_TRANSACTION, ist);
    }
  return;
}

void
ist_snd_3456xx (osip_transaction_t * ist, osip_event_t * evt)
{
  int i;

  if (ist->last_response != NULL)
    {
      osip_message_free (ist->last_response);
    }
  ist->last_response = evt->sip;

  i = __osip_transaction_snd_xxx(ist, evt->sip);
  if (i != 0)
    {
      ist_handle_transport_error (ist, i);
      return;
  } else
    {
      if (MSG_IS_STATUS_3XX (ist->last_response))
        __osip_message_callback (OSIP_IST_STATUS_3XX_SENT, ist,
                                 ist->last_response);
      else if (MSG_IS_STATUS_4XX (ist->last_response))
        __osip_message_callback (OSIP_IST_STATUS_4XX_SENT, ist,
                                 ist->last_response);
      else if (MSG_IS_STATUS_5XX (ist->last_response))
        __osip_message_callback (OSIP_IST_STATUS_5XX_SENT, ist,
                                 ist->last_response);
      else
        __osip_message_callback (OSIP_IST_STATUS_6XX_SENT, ist,
                                 ist->last_response);
    }

  if (ist->ist_context->timer_g_length != -1)
    {
      osip_gettimeofday (&ist->ist_context->timer_g_start, NULL);
      add_gettimeofday (&ist->ist_context->timer_g_start,
                        ist->ist_context->timer_g_length);
    }
  osip_gettimeofday (&ist->ist_context->timer_h_start, NULL);
  add_gettimeofday (&ist->ist_context->timer_h_start,
                    ist->ist_context->timer_h_length);
  __osip_transaction_set_state (ist, IST_COMPLETED);
  return;
}

void
ist_rcv_ack (osip_transaction_t * ist, osip_event_t * evt)
{
  if (ist->ack != NULL)
    {
      osip_message_free (ist->ack);
    }

  ist->ack = evt->sip;

  if (ist->state == IST_COMPLETED)
    __osip_message_callback (OSIP_IST_ACK_RECEIVED, ist, ist->ack);
  else                          /* IST_CONFIRMED */
    __osip_message_callback (OSIP_IST_ACK_RECEIVED_AGAIN, ist, ist->ack);
  /* set the timer to 0 for reliable, and T4 for unreliable (already set) */
  osip_gettimeofday (&ist->ist_context->timer_i_start, NULL);
  add_gettimeofday (&ist->ist_context->timer_i_start,
                    ist->ist_context->timer_i_length);
  __osip_transaction_set_state (ist, IST_CONFIRMED);
}
